3D-Printed Guitar [Prusacaster ==> Hackstercaster]

The Prusacaster is a legendary (mostly) 3D-printed guitar, based on the (even more legendary) Telecaster electric guitar design. After being asked to produce a Hackster-themed guitar to show off at Autodesk University 2025 (AU) and give away (win it here!), I came up with a new design that builds on the Prusacaster to make something even more awesome.

The design shown at AU features holes for internal lights or other wiring, addressable LEDs controlled by an Arduino Nano, and snap-in light diffusers. The second version adds a few changes to the structure as outlined below.

This writeup and video documents the first guitar build, but STL files are available for the second version, which is largely the same. The basic dimensions of the STLs found here are the same as the Prusacaster, so you can mix and match Hackstercaster printed segments with Prusacaster segments for something all your own!

Build Resources:

• The build process for this guitar is outlined in the video below and in this writeup
• Original Prusacaster CAD and print files
• More information on the Prusacaster guitar design and how to put it together
• Cook Caster design and print files - As of this writing, the design is the same as what is found here. Any updates will be uploaded there, while this page will be kept mostly static.
• Refer to instructions that come with the kit for general guitar assembly advice

Print and assemble body elements as outlined below, then follow the basic setup and wiring directions from the Harley Benton manual specified by the original Prusacaster design. You can source your own electronics if you know what you're doing, or possibly use other kits, but you may end up spending more money or time on the build. Be sure to pick up some light-gauge strings so they don't torque the body too badly!

Purchased Items:

• Guitar Kit:
  -Harley Benton kit used here, as specified by Prusacaster - $88 as of this writing, but watch out for shipping/import charges
  -Other kits may work, but are not tested, e.g. this one from Amazon.
• Filament:
  -Prusament PLA Azure Blue
  -Prusament PLA Galaxy Black
  -Prusament PLA Simply Green
  -Prusament PETG Clear
  -eSUN PLA Basic White (Amazon)
• Light gauge strings (Amazon)
• Heatset inserts (Amazon, Optional)
• M3 Screws (8mm or 10mm Amazon, Optional)

Prusacaster (PC) vs Hackstercaster (HC) comparison:

• PC: knob_holder ==> HC: knob holder-HR1
  Additions: enlarged holes (3) for heatset M3 inserts
• PC: orange_top ==> HC: orange_top-HR1
  Additions: wiring holes, hole for strap button attachment
• PC: middle_piece ==> HC: middle_piece-HR1
  Additions: deepened pickup cavities, added hole to "small_piece," enlarged holes (3) for heatset M3 inserts, enlarged ground hole
• PC: orange_middle ==> HC: orange_middle_HR1
  Additions: wiring holes, hole for strap button attachment
• PC: orange_small ==> HC: orange_small-HR1
  Additions: wiring holes
• PC: small_piece ==> HC: small_piece-HR1
  Additions: cavity for accessories (e.g. killswitch)
• PC: pickguard ==> pickguard-HR1
  Additions: branding
• New/optional: light-diffuser-no-studs-HR1
• New/optional: light-diffuser-no-studs-corner-HR1
• New/optional: Hackster-logo-circle-HR1
  Hackster logo for headstock (optional)

Note that "orange" does not correspond to the actual current color, but follows the original .step file naming convention. There is no output_jack_holder HC version, as I did not use or modify this. Instead I installed the jack holder that came with the kit.

3D-printing notes

Print one each of the above-listed STLs. I used a Prusa Core One (purchased on Amazon, also available from Prusa directly) for this build, which worked really well. This will take a while!

There are a few things to remember while printing these elements:

• middle_piece-HR1 is the most critical element to this entire design. Per the original Prusacaster instructions, print it with 7 outer layers and at 25% infill. The new design has not been tested for creep over the long term, but I suspect it will behave as well as the original for all intents and purposes.
  -Use supports, and put your printer on a solid surface (see 👇)
  -Print on .25mm STRUCTURAL setting (not the default SPEED setting)
  I had some poor results early on, which were largely rectified by paying attention to the two above tips.
• All other elements were printed with three outer layers, with either 15% or 25% infill. Two would have probably been fine.
• For the lighting elements, I used "clear" Prusament PETG filament. I would call it translucent, rather than clear (what I expected). PETG is a bit different than PLA, but the Core ONE handles it pretty well. PLA filament options may work as well.
• Again, mix and match print files as you see fit. While I certainly haven't tested every combination, things should largely work well together.
• The modified pickguard and the headstock logo were printed with white bottom layers, and an azure blue on the top. This gives it a nice white-on-blue look.
• While the Prusa CORE One is an excellent printer, before starting an epic print like the middle_piece-HR1, try a few lesser models to ensure you understand its capabilities!
• Put the Prusa CORE One on a solid base. I had some problems with layer shifting when it was on an unsturdy shelving unit. Once it was on a more stable platform, this was largely mitigated.

Heatset Inserts (optional)

In the current version, I used these inserts, with this tip for my TS100 soldering iron (link is a new version) for screws. No complaints; it seems this design addition is solid. Whether or not this is needed, see the Neck Attachment section. Note that the version shown in the video does not yet have heatset insert holes or some of the other enhancements contained in the included STLs. Again, mix and match files with the original Prusacaster design as you see fit!

Headstock Modification (Optional)

As seen in the video, I chopped off a bit of the Harley Benton headstock's material to make it look better. What they shipped me is considered a "blank" and meant to be shaped by the person putting it together. I also painted it black, which looks quite good in this context.

Body Assembly

The Prusacaster design notes that screws are optional, and in my limited experience, CNA glue holds everything together really well... Is what I wrote before September 13th, 2025. As for what happens when you DROP it on the floor, see toward the end of the video 😬. I did get it all back together before my AU trip on September 17th!

That being said, if you're going the non-screws route described in the video, I suggest you put a generous amount of glue on the attachment surfaces, put everything together on a flat surface for alignment, and attach with clamps where practical. Avoid letting glue drip out of the back, and make sure you don't end up gluing your guitar to the table!

As for why you wouldn't use screws, they are difficult to reach and install. I would recommend using the heatset inserts if you're going this route. Forming them as originally envisioned would likely be very tedious. You can even attach screws loosely first, add CNA glue (avoiding the screws themselves), then tighten them down to act as clamps.

Final Assembly (Neck/Strings/Traditional Hardware)

Put the guitar together using the Harley Benton instructions. They're not too hard to follow, with the exception of the fact that the screws don't appear to be labeled. Note that I used the silver-colored output jack that came with the guitar, not the 3D-printable output_jack_holder from the Prusacaster. It doesn't quite line up, so you may have to drill holes and/or leave two screws out.

And if you just need to put two more holes in to complete the build... don't let it drop on the floor!

With the guitar built, install your new (preferably light-gauge) strings, tune everything, and give it a strum. You may find some strings vibrate, which can potentially be fixed by adjusting the screw at the base of the headstock and/or adjusting individual strings via the bridge.

You now have a playable guitar that looks awesome! It will sound a bit different than a solid-body electric guitar, but plug it in to your amp, throw on a bit of distortion, and go wild. Or you can get it professionally set up, which probably makes a big difference.

And you're done! Or are you?

To make things really POP visually, you can also add lighting or other effects as outlined below:

Lighting and Electronics (Optional/Extra Awesome)

One of the cool things about the Hackstercaster is that it's set up for lighting and other electronics/hacks. I've provided prints for the diffusers, and the circuit is simply an Arduino Pro Nano running a stock NeoPixel strandtest routine, with the exception that the number of LEDs was changed to 9. A WS2812B strip is hooked up using jumpers and a custom solder-helper PCB, which is optional. A 9V battery powers everything, and an SPDT toggle switch powers it off to save juice.

You could also add an accelerometer, microphone, or other sensor to have it react to movements, music, or other inputs. Or perhaps make individual doodads of one sort or another for each cell. The printed hardware is there, and it's not too hard to make it light up in repeating colors. From here, the possibilities are endless. I truly hope people take my contribution to this design and make it even better.

Thanks for reading! -JC

*Note that:

• Amazon links are affiliate.
• Instructions are a bit of an amalgamation of two builds. Lighting was added to the first one, while many of the structural improvements were not implemented until build #2.
• Published under Creative Commons (4.0 International License) to follow along with original Prusacaster. Get in touch if you want to use my modifications otherwise or if you're interested in purchasing one (hi@jeremyscook.com).